The present invention pertains to a chromatographic column and the manner in which one or more ends of the column is connected to fittings or other columns and the like by means of highly efficient seal members capable of sustaining relatively high pressures, details of the structure being set forth below.
Chromatography is a process now used extensively and increasingly in analytical and preparative chemistry and wherein a stationary porous material is held in a chamber, such as a long column, while a mobile fluid material, either liquid or gaseous, is passed through the porous material. As an example, the stationary material can be an inert powder coated with a stationary liquid agent for which various distinct chemical compounds have varying affinities and, as the fluid moves through said column, the various compounds are delayed varying times by their contact with said stationary liquid agent, whereby the various chemicals emerge from the column at different times and can be detected individually by a refractometer, or other type of similar analytical apparatus relative to which the liquid flows when leaving the chromatographic column.
In chromatographic column connections to fittings and the like, which have been employed heretofore, problems have been associated with the design and use of suitable fields which are capable of remaining in fully sealed condition against pressures ranging, for example, between 1,000 and 10,000 psi, which are the ranges of pressures frequently used in liquid chromatography. Some of the sealed mechanisms developed heretofore are of such nature that when they are tightened into suitable sealing relationship, either the passage through the seal members or the end of the column which is clamped to a fitting or the like is deformed in undesirable manner, thereby necessitating the replacement of such seals, columns, or otherwise, from time to time.
In an effort to achieve appropriate seals, previous activities in the development of chromatographic equipment have resorted to various structures, some of which are relatively complex, as can be seen from the following patents which are illustrative of types of chromatographic column fittings and sealing means, at least some of which are presently in use:
U.S. Pat. No. 4,026,803--Abrahams et al--May 31, 1977 PA1 U.S. Pat. No. 4,083,702--Hartigan et al--Apr. 11, 1978 PA1 U.S. Pat. No. 4,162,977--Guillemin et al--July 31, 1979 PA1 U.S. Pat. No. 4,283,280--Brownlee--Aug. 11, 1981
The foregoing patents show various types of seals used heretofore, especially between the ends of chromatographic columns and fittings and the like connected to one or both ends thereof. The present invention is directed primarily to details and designs of sealing mechanisms which are of a relatively simple nature but highly effective to withstand the range of pressures presently employed in chromatographic apparatus. Advantages and details of the same are set forth below, as follows: